LINAC2018 - List of Keywords (bunching)

Paper	Title	Other Keywords	Page
MOPO040	Coherent Synchrotron Radiation Monitor for Microbunching Instability in XFEL	radiation, laser, electron, FEL	115
	J.H. Ko, I.S. Ko POSTECH, Pohang, Kyungbuk, Republic of Korea H.-S. Kang, C. Kim, G. Kim PAL, Pohang, Kyungbuk, Republic of Korea
	The microbunching instability is an important issue in an X-ray Free Electron Laser (XFEL). The intensity of the FEL can be reduced significantly by the microbunching instability so that the laser heater is widely used to reduce it. In the X-ray Free Electron Laser of the Pohang Accelerator Laboratory (PAL-XFEL), to directly monitor the microbunching instability, a visible CCD camera was included into the coherent radiation monitor (CRM) which uses a pyroelectric detector. It enabled us to measure the microbunching instability more clearly and optimize the FEL lasing in the PAL-XFEL.
	Slides MOPO040 [1.125 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO040
About •	paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPO092	A 3-gap Booster Cavity to Match Ion Source Potential to RFQ Acceptance	booster, rfq, ISAC, space-charge	196
	R.E. Laxdal, Z.T. Ang, T. Au, S. Kiy, S.D. Rädel, O. Shelbaya, V. Zvyagintsev TRIUMF, Vancouver, Canada
	The ISAC RFQ can accelerate ions with A/Q ration from 1 to 30 and requires an input energy of 2.04keV/u. The harsh environment of the ISAC on-line ISOL target facility makes it difficult to meet the energy for the heaviest masses. For these cases we have designed and installed a short three gap device that accelerates the beams produced at source potential to match the required energy for RFQ acceptance. The booster cavity operates at 11.7MHz, the RF frequency of the pre-buncher. The device can also be used as a second buncher to augment the acceptance in the RFQ or to improve the acceptance of higher space charge beams. The device will be described and the results of beam measurements will be given.
	Slides MOPO092 [7.627 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO092
About •	paper received ※ 14 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU1P01	Extreme High Brightness Electron Beam Generation in a Space Charge Regime	cavity, emittance, electron, space-charge	314
	A. Bacci Istituto Nazionale di Fisica Nucleare, Milano, Italy L. Faillace, M. Rossetti Conti Universita’ degli Studi di Milano & INFN, Milano, Italy
	The generation of ultra-short, low emittance and low energy spread electron bunches is nowadays a critical requirement for accelerators in plasma wave or for femto-second light sources. A new longitudinal compression scheme, based on velocity and ballistic bunching tech-niques in presence of space charge forces, allows to enter in a peculiar regime, so-called laminar bunching (LB). In this regime, the bunch is longitudinally compressed, at the expense of its transverse size, and the over-bunching is forbidden by the laminarity: going to the minimal longi-tudinal dimension the bunch is adiabatically frozen and transversally refocused. Furthermore this technique heats slightly the uncorrelated energy spread resulting in elec-tron distributions that, in case of bending paths, does not require Laser Heater devices.
	Slides TU1P01 [1.720 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TU1P01
About •	paper received ※ 12 September 2018 paper accepted ※ 31 October 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPO011	Upgrade of Heavy Ion Injector I-3 at ITEP	acceleration, heavy-ion, emittance, laser	346
	N.N. Alexeev, P.N. Alekseev, V. Andreev, T. Kulevoy, A.D. Milyachenko, V.I. Nikolaev, Yu.A. Satov, A. Shumshurov, A. Zarubin ITEP, Moscow, Russia
	Heavy ion injector I-3 represents two-gap 2.5 MHz resonator with accelerating voltage 2x2 MV. It‘s used with laser ion source for acceleration of heavy ions in wide range of charge to mass ratio. As a result of modernization, injector structure will be supplemented by the second two-gap resonator, rf voltage will be increased to 3x4 MV and accelerated beam structure has to be improved by increasing accelerating frequency to 5 MHz. Design features of upgraded linac and peculiarity of beam dynamics for different types of ions are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO011
About •	paper received ※ 03 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPO042	An Optimization Method of the Nose-cone Buncher Cavity	cavity, simulation, proton, radiation	778
	W.L. Liu, P.T. Cong, Z.M. Wang NINT, Shannxi, People’s Republic of China H. Jiang, S.X. Zheng TUB, Beijing, People’s Republic of China
	The nose-cone buncher cavity is widely used on proton accelerators. It’s important to properly optimize the cavity geometry for fine RF performance. Howev-er, currently the optimization is usually carried out manually and the criteria are not objective enough. In this paper, an optimization method using the multi-objective, multi-variable optimization approach is presented. The geometry and RF parameters are con-sidered as the variables and objectives respectively. The goal function is defined as the weighted sum of multiple RF parameters. The multi-variable functions are approximately derived from the single-variable functions based on electromagnetic simulation. And an optimization code is developed accordingly which has been applied to the XiPAF debuncher optimization.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO042
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPO040

Coherent Synchrotron Radiation Monitor for Microbunching Instability in XFEL

radiation, laser, electron, FEL

115

J.H. Ko, I.S. Ko
POSTECH, Pohang, Kyungbuk, Republic of Korea
H.-S. Kang, C. Kim, G. Kim
PAL, Pohang, Kyungbuk, Republic of Korea

The microbunching instability is an important issue in an X-ray Free Electron Laser (XFEL). The intensity of the FEL can be reduced significantly by the microbunching instability so that the laser heater is widely used to reduce it. In the X-ray Free Electron Laser of the Pohang Accelerator Laboratory (PAL-XFEL), to directly monitor the microbunching instability, a visible CCD camera was included into the coherent radiation monitor (CRM) which uses a pyroelectric detector. It enabled us to measure the microbunching instability more clearly and optimize the FEL lasing in the PAL-XFEL.

Slides MOPO040 [1.125 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO040

About •

paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPO092

A 3-gap Booster Cavity to Match Ion Source Potential to RFQ Acceptance

booster, rfq, ISAC, space-charge

196

R.E. Laxdal, Z.T. Ang, T. Au, S. Kiy, S.D. Rädel, O. Shelbaya, V. Zvyagintsev
TRIUMF, Vancouver, Canada

The ISAC RFQ can accelerate ions with A/Q ration from 1 to 30 and requires an input energy of 2.04keV/u. The harsh environment of the ISAC on-line ISOL target facility makes it difficult to meet the energy for the heaviest masses. For these cases we have designed and installed a short three gap device that accelerates the beams produced at source potential to match the required energy for RFQ acceptance. The booster cavity operates at 11.7MHz, the RF frequency of the pre-buncher. The device can also be used as a second buncher to augment the acceptance in the RFQ or to improve the acceptance of higher space charge beams. The device will be described and the results of beam measurements will be given.

Slides MOPO092 [7.627 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO092

About •

paper received ※ 14 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU1P01

Extreme High Brightness Electron Beam Generation in a Space Charge Regime

cavity, emittance, electron, space-charge

314

A. Bacci
Istituto Nazionale di Fisica Nucleare, Milano, Italy
L. Faillace, M. Rossetti Conti
Universita’ degli Studi di Milano & INFN, Milano, Italy

The generation of ultra-short, low emittance and low energy spread electron bunches is nowadays a critical requirement for accelerators in plasma wave or for femto-second light sources. A new longitudinal compression scheme, based on velocity and ballistic bunching tech-niques in presence of space charge forces, allows to enter in a peculiar regime, so-called laminar bunching (LB). In this regime, the bunch is longitudinally compressed, at the expense of its transverse size, and the over-bunching is forbidden by the laminarity: going to the minimal longi-tudinal dimension the bunch is adiabatically frozen and transversally refocused. Furthermore this technique heats slightly the uncorrelated energy spread resulting in elec-tron distributions that, in case of bending paths, does not require Laser Heater devices.

Slides TU1P01 [1.720 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TU1P01

About •

paper received ※ 12 September 2018 paper accepted ※ 31 October 2018 issue date ※ 18 January 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPO011

Upgrade of Heavy Ion Injector I-3 at ITEP

acceleration, heavy-ion, emittance, laser

346

N.N. Alexeev, P.N. Alekseev, V. Andreev, T. Kulevoy, A.D. Milyachenko, V.I. Nikolaev, Yu.A. Satov, A. Shumshurov, A. Zarubin
ITEP, Moscow, Russia

Heavy ion injector I-3 represents two-gap 2.5 MHz resonator with accelerating voltage 2x2 MV. It‘s used with laser ion source for acceleration of heavy ions in wide range of charge to mass ratio. As a result of modernization, injector structure will be supplemented by the second two-gap resonator, rf voltage will be increased to 3x4 MV and accelerated beam structure has to be improved by increasing accelerating frequency to 5 MHz. Design features of upgraded linac and peculiarity of beam dynamics for different types of ions are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO011

About •

paper received ※ 03 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPO042

An Optimization Method of the Nose-cone Buncher Cavity

cavity, simulation, proton, radiation

778

W.L. Liu, P.T. Cong, Z.M. Wang
NINT, Shannxi, People’s Republic of China
H. Jiang, S.X. Zheng
TUB, Beijing, People’s Republic of China

The nose-cone buncher cavity is widely used on proton accelerators. It’s important to properly optimize the cavity geometry for fine RF performance. Howev-er, currently the optimization is usually carried out manually and the criteria are not objective enough. In this paper, an optimization method using the multi-objective, multi-variable optimization approach is presented. The geometry and RF parameters are con-sidered as the variables and objectives respectively. The goal function is defined as the weighted sum of multiple RF parameters. The multi-variable functions are approximately derived from the single-variable functions based on electromagnetic simulation. And an optimization code is developed accordingly which has been applied to the XiPAF debuncher optimization.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO042

About •

paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)